Question

If the mean bond length increases with temperature in material, then the material exhibits:

• A. Thermal stability
• B. Thermal expansion
• C. Thermal contact
• D. Thermal conductivity

Hint:

Thermal expansion is the result of increased atomic vibrations leading to greater mean interatomic distances as temperature rises.

Answer 1

The Correct Option is B

When a material is heated, the thermal energy causes atoms to vibrate more intensely. As a result, the average distance between atoms (i.e., mean bond length) increases.
This phenomenon leads to an overall increase in the dimensions of the material — a behavior known as thermal expansion.
Thermal expansion is thus directly related to the increase in bond length due to temperature rise.
Other options like thermal conductivity and stability are related to different thermal behaviors but not to bond length change.